6-cyclopentylidenehexanal

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From May 21, 2013 to May 31, 2013

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

This study was performed according to OECD Guideline 203 with GLP certificate. All validity criteria were fulfilled. However, this study is considered reliable with restrictions for the following reasons: - The treatment solutions were prepared with a solvent (acetone), which is not the best method at the time being but in acceptable quantity (0.125 mL/L). - The test type (open or closed conditions) was not reported in the study report. - At the highest tested concentration (16 mg/L, nominal value) visual examination proved that part of the test item was not solubilised and therefore physical effects are expected. However, approximately 50% mortality was observed at 5.5 mg/L (measured value; concentration lower than the water solubility), the LC50 value is acceptable but possible overestimation of the toxicity as the test solutions were not prepared individually.

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

July 1992

Deviations:

yes

Remarks:

Solvent was used and visual observation showed incomplete solubilisation of the test item at the highest concentration (16 mg/L, nominal value). Possible overestimation of the toxicity.

GLP compliance:

yes (incl. QA statement)

Remarks:

Inspection date on 14 June 2012 / GLP certificate signed on 10 January 2013

Specific details on test material used for the study:

- Storage condition: Room temperature protected from direct sun light

Analytical monitoring:

yes

Details on sampling:

The test item concentrations were measured before and after each renewal/adjustment.

Vehicle:

yes

Remarks:

acetone

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The treatment solutions were prepared in acetone. The different treatment solutions are shown in Table 6.1.1/1 in "Any other information on materials and methods incl. tables", as they were prepared (nominal concentrations).
- Controls: water control and solvent control
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): acetone
- Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)): 0.125 mL/L
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): At the highest tested concentration (16 mg/L, nominal value) visual examination proved that part of the test item was not solubilised. Indeed, oily material was observed at the surface of the aqueous volume.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Strain: Brachidanio rerio
- Source: Not communicated
- Age at study initiation (mean and range, SD): no details
- Length at study initiation (length definition, mean, range and SD): mean length was measured out from 15% of the total population, taken at random: 2.0 +/- 0.2 cm.
- Weight at study initiation (mean and range, SD): no details
- Method of breeding: no details
- Maintenance of the brood fish: Fish were maintained at 23 +/- 2 °C, with a 16h/8h light/dark cycle, in the same reconstituted water as used for testing.
- The fish were kept unfed during the exposure period.

Test type:

semi-static

Water media type:

freshwater

Remarks:

ISO test water (according to ISO 6341) was freshly reconstituted by dilution of mineral stock solutions in pure water.

Limit test:

no

Total exposure duration:

96 h

Test temperature:

The temperature of the test solutions were within 22.0 and 25.0°C and did not deviate by more than 1.5°C in any one case throughout each successive period or when renewing the test medium. The only exception was for the 5.5 mg/L test item treatment on day 1. A deviation of 1.6°C was observed over the first day of testing, from 24.6 down to 23.0°C. Further observations proved that 24.6°C was a temporary value, and the aqueous volume remained within 22.7 - 23.3°C afterwards.

pH:

The pH values remained within 7.8 and 8.2 at the beginning of each media renewal and decreased down to 7.5-7.8 at the end of each successive period.

Dissolved oxygen:

Dissolved oxygen concentrations was more than 80% of the saturation level for every test item treatment and for the controls in the new media and the old media.

Salinity:

Not applicable

Nominal and measured concentrations:

- Nominal treatment concentrations: 1.0, 2.0, 4.0, 8.0 and 16.0 mg/L.
- Measured concentrations: See table 6.1.1/2 in "Any other information on results incl. tables".
The initial concentrations did not deviate by more than 10% from the nominal values except at 16.0 mg/L in this case recovery of the nominal concentration was only 80.7% and visual examination proved that full solubilisation of the test item was difficult to achieve at such a high concentration: oily material was observed at the surface of the aqueous volume. On day 1, care was taken that even dispersion was achieved before sampling and in this case, recovery of the test item represented 93.8% of the nominal value. The successive analytical assessments proved that the test item treatments regularly decreased down to approximately 40-50% of the nominal values over a 15h standing period, and to 50-75% of the nominal values over a 9h standing period. Based on mean measured concentrations over each successive period, and duration of each successive period, mean exposure concentrations were calculated as 0.7 - 1.4 - 2.8 - 5.5 and 10.1 mg/L instead of 1.0 - 2.0 - 4.0 - 8.0 and 16.0 mg/L.

Details on test conditions:

TEST SYSTEM
- Test vessel: 8.0 L capacity glass containers
- Type (delete if not applicable): open or closed condition not reported in the study report
- Material, size, headspace, fill volume: filled with 4L of reconstituted water
- Renewal rate of test solution (frequency/flow rate): the test item treatments were renewed daily and further adjusted in the course of the days.
- No. of organisms per vessel: 7 fish per aquarium
- No. of vessels per concentration (replicates): one replicate unit for each the five test treatments with 7 fish per aquarium
- No. of vessels per control (replicates): one replicate unit for the controls with 7 fish per aquarium
- No. of vessels per vehicle control (replicates): one replicate unit for the controls with 7 fish per aquarium

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: ISO test water (according to ISO 6341) was freshly reconstituted by dilution of mineral stock solutions in pure water.

OTHER TEST CONDITIONS
- Photoperiod: 16h light per day
- Light intensity: <500 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : The test units were inspected for mortality 24h, 48h, 72h and 96h after initiation. Any abnormal behavior or appearance, if any, was reported.

TEST CONCENTRATIONS
- Range finding study : yes
- Test concentrations: 0.04, 0.20, 1.0, 5.1 and 25.3 mg/L
- Results used to determine the conditions for the definitive study: The viability was not affected in the 0.04 and 0.20 mg/L. At 25.3 mg/L, all the specimens had died after 24 hours of testing. Two specimens died in the 1.0 mg/L test item treatment but this was not confirmed at 5.1 mg/L. The phenomenon was not considered as a treatment induced effect. At 5.1 mg/L the swimming behaviour was affected: no or few movements were observed.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

5.2 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CL: 2.4 - 11.4 mg/L

Duration:

96 h

Dose descriptor:

other: Highest tested concentration without observed effect

Effect conc.:

2.8 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

No mortality was observed in the water control and the solvent control. The viability was not affected for test item treatments up to and including 2.8 mg/L. At 10.1 mg/L, all the specimens had died after 24 hours of testing. At 5.5 mg/L, the specimens exhibited no or few movements after 24 hours of testing. One specimen was considered as died on day 3, and at the end of test 4 specimens had died. See table 6.1.1/3 in "Any other information on results incl. tables".

Results with reference substance (positive control):

Sensitivity to Potassium dichromate was assessed. The measured values for 96h-LC50 were within the expected interval of 50-250 mg/L.
Raw data not provided in the study report

Sublethal observations / clinical signs:

Table 6.1.1/2: Definitive test - % recovery of the test item treatments throughout the test period

	Nominal treatment concentrations
	1.0 mg/L	2.0 mg/L	4.0 mg/L	8.0 mg/L	16.0 mg/L
Initial (T0)	1.04 mg/L 103.4%	2.12 mg/L 106.1%	3.83 mg/L 95.6%	7.35 mg/L 91.8%	12.92 mg/L 80.7%
T0+6h – Old media	0.83 mg/L 82.9%	1.36 mg/L 67.8%	2.35 mg/L 58.6%	3.84 mg/L 48.0%	7.26 mg/L 45.3%
T0+6h – New media	0.96 mg/L 95.8%	1.79 mg/L 89.5%	3.47 mg/L 86.7%	6.98 mg/L 87.2%	13.98 mg/L 87.3%
T0+21h – Old media	0.52 mg/L 52.0%	0.90 mg/L 44.7%	1.90 mg/L 47.5%	3.94 mg/L 49.2%	7.54 mg/L 47.1%
T0+21h – New media	1.05 mg/L 104.9%	2.00 mg/L 99.9%	3.96 mg/L 98.9%	7.50 mg/L 93.7%	15.02 mg/L 93.8%
T0+30h – Old media	0.75 mg/L 74.5%	1.21 mg/L 60.6%	2.10 mg/L 52.6%	4.26 mg/L 53.2%	(1)
T0+30h – New media	1.01 mg/L 100.8%	1.92 mg/L 95.7%	3.87 mg/L 96.6%	6.94 mg/L 86.6%	(1)
T0+45h – Old media	0.48 mg/L 48.2%	0.87 mg/L 43.6%	2.01 mg/L 50.1%	4.06 mg/L 50.7%	(1)
T0+45h – New media	1.13 mg/L 113.1%	2.19 mg/L 109.4%	3.92 mg/L 98.0%	7.94 mg/L 99.1%	(1)
T0+54h – Old media	0.71 mg/L 71.1%	1.34 mg/L 66.8%	2.32 mg/L 58.0%	4.79 mg/L 59.8%	(1)
T0+54h – New media	1.03 mg/L 102.5%	1.97 mg/L 98.6%	4.43 mg/L 110.6%	9.85 mg/L 123.0%	(1)
T0+68h – Old media	0.37 mg/L 37.3%	0.82 mg/L 41.0%	1.82 mg/L 45.4%	3.81 mg/L 47.6%	(1)
T0+68h – New media	1.14 mg/L 113.9%	2.19 mg/L 109.3%	4.13 mg/L 103.2%	7.85 mg/L 98.0%	(1)
T0+78h – Old media	0.70 mg/L 69.8%	1.26 mg/L 62.8%	2.25 mg/L 56.3%	4.13 mg/L 51.5%	(1)
T0+78h – New media	0.93 mg/L 92.4%	1.78 mg/L 88.9%	3.51 mg/L 87.6%	7.29 mg/L 91.0%	(1)
End of test	0.35 mg/L 35.0%	0.79 mg/L 39.5%	2.19 mg/L 54.8%	3.33 mg/L 41.6%	(1)
Geometric mean	0.7 mg/L	1.4 mg/L	2.8 mg/L	5.5 mg/L	10.1 mg/L

 

Table 6.1.1/3: Definitive test - Observed mortality

	Mortality %
	24h	48h	72h	96h
Water control	0,0	0,0	0,0	0,0
Solvent control	0,0	0,0	0,0	0,0
Test substance
0,7 mg/L	0,0	0,0	0,0	0,0
1,4 mg/L	0,0	0,0	0,0	0,0
2,8 mg/L	0,0	0,0	0,0	0,0
5,5 mg/L	0,0	0,0	14,3	57,1
10,1 mg/L	100	100,0	100	100

Validity criteria fulfilled:

yes

Remarks:

Mortality in the controls did not exceed one fish at the end of the test; Constant environmental conditions were maintained throughout the test; The dissolved oxygen concentration was at least 60 per cent of saturation value throughout the test

Conclusions:

The acute toxicity of the test item to Danio rerio has been investigated and gave a 96-hour LC50 value of 5.2 mg/L with 95% confidence limits of 2.4 to 11.4 mg/L; based on geometric mean measured concentrations. The highest concentration without observed effect was 2.8 mg/L.

Executive summary:

This study was performed according to OECD Guideline 203 with GLP statement, to assess the acute toxicity of the test substance to Danio rerio.

Following a preliminary range-finding study, fish were exposed, in groups of 7 fish per aquarium, to an aqueous dispersion of the test material (with solvent) over a range of nominal concentrations of 1.0, 2.0, 4.0, 8.0 and 16.0 mg/L, corresponding to geometric mean measured concentrations of 0.7, 1.4, 2.8, 5.5 and 10.1 mg/L, for a period of 96 hours under semi-static test conditions.

Based on geometric mean measured concentrations, the 96 hours LC50 for the test material to Danio rerio was 5.2 mg/L with 95% confidence limits of 2.4 - 11.4 mg/L. The highest concentration without observed effect was 2.8 mg/L.

All validity criteria were fulfilled. However, this study is considered reliable with restrictions for the following reasons:

- The treatment solutions were prepared with a solvent (acetone), which is not the best method at the time being but in acceptable quantity (0.125 mL/L).

- The test type (open or closed conditions) was not reported in the study report.

- At the highest tested concentration (16.0 mg/L, nominal value) visual examination proved that part of the test item was not solubilised and therefore physical effects are expected. However, approximately 50% mortality was observed at 5.5 mg/L (measured value; concentration lower than the water solubility), the LC50 value is acceptable but possible overestimation of the toxicity as the test solutions were not prepared individually.

Description of key information

OECD Guideline 203, GLP, key study, validity 2:

96h-LC50 (Danio rerio) = 5.2 mg/L (95% CL: 2.4 - 11.4 mg/L), based on geometric mean measured concentrations.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

5.2 mg/L

Additional information

One experimental study is available to assess the short-term toxicity of the registered substance to fish.

This study (Phytosafe, 2013), performed according to OECD Guideline 203 with GLP statement, assess the acute toxicity of the registered substance to Danio rerio. Following a preliminary range-finding study, fish were exposed, in groups of 7 fish per aquarium, to an aqueous dispersion of the test material (with solvent) over a range of nominal concentrations of 1.0, 2.0, 4.0, 8.0 and 16.0 mg/L, corresponding to geometric mean measured concentrations of 0.7, 1.4, 2.8, 5.5 and 10.1 mg/L, for a period of 96 hours under semi-static test conditions.

Based on geometric mean measured concentrations, the 96 hours LC50 for the test material to Danio rerio was 5.2 mg/L with 95% confidence limits of 2.4 - 11.4 mg/L. The highest concentration without observed effect was 2.8 mg/L.

All validity criteria were fulfilled. However, this study is considered reliable with restrictions for the following reasons:

- The treatment solutions were prepared with a solvent (acetone), which is not the best method at the time being but in acceptable quantity (0.125 mL/L).

- The test type (open or closed conditions) was not reported in the study report.

- At the highest tested concentration (16.0 mg/L, nominal value) visual examination proved that part of the test item was not solubilised and therefore physical effects are expected. However, approximately 50% mortality was observed at 5.5 mg/L (measured value; concentration lower than the water solubility), the LC50 value is acceptable but possible overestimation of the toxicity as the test solutions were not prepared individually.